Engineering topics
Publications and source records attributed to Katzoff, S..
A simple siphon method is described for determining the resistivities of thin heat pipe wicks as a function of the pressure difference between the liquid in the wick and the vapor above it. The method was applied to wicks of one layer and two layers of 100 mesh (40 per centimeter) stainless steel screens diffusion bonded to stainless steel substrates. Some possible improvements in the method are suggested.
The thermal radiation from the earth incident on a spherical satellite depends on the angular distribution of earth-emitted radiation. An analysis is presented of this dependency, and calculated results are given, based on a published limb-darkening curve for the earth. The curve was determined from Tiros data, and is a statistical average over the entire globe between 75 deg latitude. The computed effect of limb darkening was 1.8 percent at 900 km altitude, 2.5 percent at 500 km altitude, and 3.0 percent at 300 km altitude. Below 300 km, it increased rapidly with decreasing altitude. Discussion is included of various other problems inherent in the use of orbiting spheres and stabilized flat plates to measure the heat radiated from the earth.
Analytical methods are developed for estimating the circumferential and longitudinal temperature distributions in a large space telescope, idealized as a simple insulated tube with a flat mirror across one end. The effects of wall conduction, multilayer insulation, thermal coatings, heat pipes, and heated collars are analyzed, with numerical examples. For most of the study, the only thermal input to the tube was assumed to be from steady solar irradiation from one side, as in a geosynchronous orbit. Unsteady heat flow through the insulation, as in alternating sunlight and shadow of a low orbit, is briefly discussed.
Quantitative determination of optical imperfection by mathematical analysis of Foucault knife edge test pattern in large orbiting telescope
Precision temperature control of large orbiting telescopes
Heat pipes and vapor chambers for thermal control of spacecraft, noting design and application
Heat pipes and vapor chambers for thermal control of spacecraft, noting design and application
Review of studies on heat pipes and vapor chambers and their application to thermal control of spacecraft
For visualizing flow characteristics in wind tunnel tests, model surfaces are smeared with any common petroleum-base oils. These fluoresce under ultraviolet light and the flow patterns are readily visualized.
The radiations that significantly affect the thermal balance of an earth satellite are: (1) Direct solar radiation. (2) Solar radiation reflected from the earth. (3) Thermal radiation from the earth. The total energy and the spectrum of the direct solar radiation are known to adequate accuracy. The solar radiation reflected from the earth is known with considerably less certainty. The earth's average albedo is about 35 percent. Different latitudes, however, have average albedos above or below this value. Furthermore, there is considerable variation with time and place, since the reflectance of solar radiation is determined by the sun's elevation angle, the nature of the terrain (desert, forest, snow, water, etc.) and the weather (absolute humidity, cloudiness, height and nature of clouds, etc.). Accordingly, it would be desirable to have statistically reasonable upper and lower limits for the reflected solar radiation for use in thermal-balance design studies.
A flow-visualization technique, known as the fluorescent-oil film method, has been developed which appears to be generally simpler and to require less experience and development of technique than previously published methods. The method is especially adapted to use in the large high-powered wind tunnels which require considerable time to reach the desired test conditions. The method consists of smearing a film of fluorescent oil over a surface and observing where the thickness is affected by the shearing action of the boundary layer. These films are detected and identified, and their relative thicknesses are determined by use of ultraviolet light. Examples are given of the use of this technique. Other methods that show promise in the study of boundary-layer conditions are described. These methods include the use of a temperature-sensitive fluorescent paint and the use of a radiometer that is sensitive to the heat radiation from a surface. Some attention is also given to methods that can be used with a spray apparatus in front of the test model.
A solution has been obtained for the complete tunnel-interference flow for a lifting vortex in a two-dimensional slotted tunnel. Curves are presented for the longitudinal distribution of tunnel-induced downwash angle for various values of the boundary openness parameter and for various heights of the vortex above the tunnel center line. Some quantitative discussion is given of the use of these results in calculating the tunnel interference for three-dimensional wings in rectangular tunnels with closed side walls and slotted top and bottom.
Explore the source record for details and available documents.